Hot-air heating system



Aug. 31 1926.

' v J. C. STILLMAN HOTAIR HEATING SYSTEM Filed sept. io,

1925 2 Sheets-Sheet 2 linatented Aug. El, i926.

rasant lOl-IN C. STILLMAN, OF APPLETG, VSCONSIN.

HOT-AR SYSTEIV.

Application filed September 10,

This invention relates to hot air heating systems, and is an improvement over that disclosed in my United States Fat-ent No. 1,110,116@ granted September 15, 1914 foi furnace for hot air heating systems.

Y rlhis invention has the same general objects as those disclosed in the patent noted above.

Further objects are to provide a furnace in which the incoming air for the main air return is preheated prior to its entry into the furnace, the normally wasted heat in the smoke pipe or iiue pipe being used for this purpose. Y

Further objects are to provide an attachment which may be applied to standard furnaces with a very small amount of change in the standard equipment, and which will provide for this preheating of the incoming` or cold air for the furnace, which is equipped with means for first connecting the furnace directly with the chimney and, thereafter, when the fire has become stable, connecting the furnace with the apparatus and eXtraeting heat from the waste gases.

Further objects are to provide a pre-heater for hot air furnaces which may be sold and handled as a separate unit, which may be quickly applied to existing types of furnaces, which is provided with means for permitting its ready cleaning, and which is provided with easily removable screens adapted to prevent the delivery of dust and other material into the furnace.

An embodiment of the invention is shown in the accompanying drawings, in which Figure l is a sectional view through the device showing a furnace partly in section associated therewith, such view corresponding to a section on the line 1 1 of Figure 2.

Figure 2 is a plan view of the structure shown in Figure 1, such view being partly broken awayvand partly in section.

Figure ,3 is a sectional view on the line 3-3 of Figure 2.

Referring to the drawings, it will be seen that the conventional type of furnace has been illustrated in which any suitable heating drum r member 1 is encased in an outer shell 2, and in which the furnace is provided with a delivery portion or pipe 3,. The smoke Hue l extends from the combustion chamber or main heating member 1 outwardly through the outer shell in the usual manner. A return air duct 5 for the cold air opens into the lower portion of the casing 1925. serial ive. 5115433.

2, shown in Figure 1. The attachment comprises a box-like outer casing 6 which surrounds a smaller bo'X-lilre Casing 7. rlhe casing 6 is directly connected to the cold air inlet 5 of the furnace and is provided with an inlet portion 8 adapted to be connected 'to the cold air return of the system. rl`his inlet portion 8 is provided with a plurality of screens 9 which are slidably carried in frames 10, which frames being positioned within suitably grooved portions 11 of the inlet portion 8. lf desired, handles may be provided whereby the screens may be laterally withdrawn with the utmost ease forl cleaning or renewal.

Referring particularly to Figures 2 and 3, it will be seen that the smoke pipe 4l is proviucd with two branches, one branch 13 is the flue pipe and passes directly to the chimney, and the other branch 14- extends laterally therefrom and is curved downwardly, as shown in Figure 3. rlhis branch joins a horizontal portion 15 which extends through the outer casing 6 of the pre-heater and opens into the inner chamber 7 there of. This inner chamber 7 is provided with a plurality of baille plates such as indicated at 16. Further, a short vertical pipe 17 extenes upwardly from the inner chamber 7 or box of the pre-heater and opens into the flue pipe 13.

Referring to Figures 1 and 3, it will be noted that the inner box or compartment 7 of the pre-heater is supported by angle iron legs 18 which space .it upwardly from the bottom of the outer shell (i and thus permit free circulation of air beneath as well as over and around such inner compartment, as shown by the arrows in Figure 1.

For cleaning purposes a relatively large cap 19 is provided in the upper wall of the outer shell 6 and a smaller cap 20 is provided immediately below it in the upper wall of the compartment 7. The smaller cap is such a size that it may be removed through the opening in the upper wall of the outer compartment. This provides for easy cleaning of the device and affords ready access to the inner compartment 7 to permit removal of ashes or soot.

In order to control the direction of flor.' of the products of combustion a pair of dampers or valves 21 and 22 are provided, the valve 21 controlling communication between the pipe l of the furnace and the flue pipe 13, and the valve 22 controlling com- Wardly extending control chain or rink 2o ltfis to be noted particularly from refere ce to TFigure 3, that the arm 25 rocks from one side of dead center to the other, so that a single chain or link 2S may be employed for its manipulation. rlhus, when it is quickly pulled upwardly, the arm is rocked from one side to the other. Ubviously, a subsequent quick upward pull Will rock the arm to the other side. Although this mechanism has been found to Work Well, it obviously may be varied, as desired.

rhe operation of the apparatus is as follo\vs:-\Vhen the iire is first started or when fresh fuel is added, the damper is closed and the damper 2l is opened, thus connecting the furnace directly with the chimney. After the lire is Well started, the damper 22 is opened and the damper 2i is closed, as shown in Figure 3 of the drawing. lhen the dempers are in this last dcscribed position, the products of eonibus tion pass through the branch lei, through the chamber 7 of the pre-heater and through the pipe 17 to the fiue pipe 13. The battles 16 cause the hot gases to contact With all por-A tions of the Walls of the inner compartment 7. rthe incoming air strikes this hot compartment and is preheated prior to its delivery to the furnace. The link and crank mechanism cause the dampers to operate simultaneously closing one and opening` the other. Obviously stops may be employed to prevent the cranks from stoppingon dead center.

it has been found that this type of device is economical and saves a considerable amount of fuel, and it is to be noted particularly that it may be applied to standard types of furnaces Without requiring elabcrate changes, merely necessitating the interoosition of the device between the furnace and the cold air return and between the furnace and the flue.

lt is to be noted further that the device may be installed by ordinary tinsmiths Without requirin` alteration in the setting of 1the furnace or any elaborate changes of this nature.

Although Jhe invention has been described in considerable detail, it is to be understood that the invention may be variously embodied and is, therefore, to be lim ited only as claimed.

.l claim:

fr pre-heater for a hot air furnace having,` an inlet for the air and having a smoke pipe, said pre-heater comprising' a u ry structure consisting` of an outer shell, an inner compartment carried therein and supported out of Contact with said outer compartaient, a flue pipe leading from said inner con'ipartment, a second pipe leading n 'the smoke pipe of said furnace into compartment and to said flue pipel dampers for controllim@` the direction of io' of products of combustion either ,Y

Lh'gougrh said inner compartment or through said fine pipe, one of said dempers being; located in the pipe leading to the flue and the other of said dampers being located in the `pipe leading to said compartment, said inner compartment and said outer shell hai'- ing aligning apertures, the aperture in the outer shell being larger than the aperture in the inner compartment, and covers for said apertures, whereby the cover for the inner compartment may be removed through the aperture in the outer shell.

in testimony that I claim the foregoing- I have hereunto set my hand at Appleton, in the county of Uutagamie and State of lVisconsin. 

